Recent studies into the functions of histone methylation have revealed this histone modification to have many roles in gene regulation. In budding yeast, Set2 is the sole H3 lysine 36 methyltransferase. It functions to either mono-, di, or tri-methylate this residue. Methylation of lysine 36 has been associated both with gene repression and transcription elongation, yet how methylation functions in these roles is not understood. To determine the role of H3 lysine 36 methylation in regulating gene expression, a chromatin immunoprecipitation approach, coupled with microarray analysis, will be used to determine the genomic locations of the three different methyl forms of K36. A gene specific chromatin immunoprecipitation approach will be used subsequent to the microarray analysis to precisely define within the body of genes where the individual methylation marks are localized. Furthermore, proteins that bind to the different methylated forms of H3 K36 to mediate Set2's downstream effects on gene expression will be characterized and their role in regulating gene activity assessed. These experiments will further elucidate the functions of the different methyl K36 forms in regulating gene activity and chromatin function.